Once a natural disaster damages essential infrastructure services, such as roads, bridges, electric power and potable water, the priority is to restore these services as soon as possible. Under normal circumstances, the planning, design and construction of complex infrastructure projects requires an extended period of time that in many cases lasts for years. The reconstruction of essential services after a disaster is complex not only because the amount of time that can be devoted to planning is extremely limited, but also because government agencies and their officials are under public scrutiny. The press and political institutions frequently criticize thereaction time and decisions of public officials, which increases the complexity of the projects. This article uses a five-dimensional project management model (5DPM) to identify and manage the sources of complexity in emergency projects. The article describes the sources of complexity in reconstruction projects after natural disasters hit the islands of New Zealand and Puerto Rico causing great devastation. The natural disasters analyzed in this article are the earthquakes of 2010 and 2011 in New Zealand and the hurricanes Irma and Maria in 2017 in Puerto Rico. The islands, due to their geographical location, faced similar challenges in terms of the shortage of workers, and materials and equipment for reconstruction, which had to be imported. The shortage negatively impacted the response time to the emergency, the perception of the press, and public opinion about the proper handling of the emergencies. The article analyzes the sources of complexity in the reconstruction of the damaged infrastructure and concludes that the sociopolitical context is often the most complex dimension when reconstruction projects are carried out in an expeditious manner.